Perceived impact of the COVID-19 pandemic on residency training in American College of Veterinary Anesthesia and Analgesia programs in North America: a quantitative survey.

OBJECTIVE: To characterize the extent of the impact of the COVID-19 pandemic on aspects of the anesthesia residency experience from the perspective of American College of Veterinary Anesthesia and Analgesia (ACVAA) mentors and trainees. This includes the residency interview process, didactic training and availability and variety of clinical cases for resident learning. STUDY DESIGN: Cross-sectional, online, anonymous voluntary survey. SAMPLE POPULATION: A total of 58 respondents, representing 30 residency program mentors and 28 residents. METHODS: Surveys were distributed by email to 94 residency program mentors and 70 residents, representing programs and residents registered with the ACVAA during the years of 2019-2021. Anonymous links to an online survey were provided via a link embedded in the email. Questions included perceived impacts (-5 to +5 scale) on didactic and clinical training, case distribution, workload, residency application and selection process, and mental health. Responses were summarized with descriptive statistics [median (IQR) or mean ± SD]. RESULTS: The overall survey response rate was 31.9% (30/94) and 40.0% (28/70) for resident program mentors and residents, respectively. There was a negative perceived impact on overall residency training reported: -1.0 (IQR -2.0 to 0) for program mentors and -1.5 ± 1.5 for residents. The reported perceived impact of travel limitations on case log completion was -2.0 (IQR -4.0 to -1.0) for program mentors and -2.4 ± 2.0 for residents. Program mentors and residents had incongruent feelings on the impact of the pandemic on work hours, with residents reporting a perceived increase in work hours [+2.1 ± 2.1 versus 0 (IQR -1.0 to 0)]. CONCLUSIONS: Residency program mentors and residents generally agreed that the COVID-19 pandemic had negatively impacted multiple aspects of residency interview and training process. A broader, objective analysis of veterinary anesthesia training programs is required to fully elucidate the scale of the impact on veterinary anesthesia training.

Description of an ultrasound-guided rectus sheath block injection technique and the spread of dye in calf cadavers.

OBJECTIVES: To describe an ultrasound-guided rectus sheath (RS) block technique in calves with injections of methylene blue and assess the extent of injectate spread and nerve staining in calf cadavers. STUDY DESIGN: Prospective, experimental, blinded cadaveric study. ANIMALS: A total of 16 calf cadavers weighing 30.7 ± 7.1 kg. METHODS: Using an ultrasound-guided, in-plane technique, each cadaver was injected with both a low (LV; 0.25 mL kg-1) and high (HV; 0.5 mL kg-1) volume of methylene blue dye. Volumes were randomly assigned to the left or right hemiabdomen. Ultrasound imaging was scored based on landmarks and needle visualization, and duration to perform injections were assessed. Dissections were performed immediately after injections. Staining of ventral branches of spinal nerves and the extent of dye spread were recorded by an anatomist unaware of treatment allocation. RESULTS: The number of nerves stained in treatments LV and HV were 2.3 ± 1.7 and 4.4 ± 1.3, respectively (p = 0.0001). Branches of thoracic nerves T7-13 and lumbar nerves L1-2 were completely stained 6.3%, 6.3%, 31.3%, 62.5%, 56.3%, 37.5%, 31.3%, 6.3% and 0%, respectively, in treatment LV and 0%, 12.5%, 50%, 93.8%, 100%, 93.8%, 62.5%, 25% and 6.3%, respectively, in treatment HV. Ultrasound imaging was scored excellent in most cadavers and needle visualization deemed excellent in all injections. The mean duration to perform RS injections in both treatments was 2 (range, 1-6) minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Nerve staining results from treatment HV suggest that this RS injection technique could be clinically useful in ventral midline surgical procedures, including umbilical procedures, in calves. This study supports future clinical trials in calves.

Evaluation of ultrasound-guided pecto-intercostal block in canine cadavers.

OBJECTIVE: To describe the technique for performing an ultrasound-guided pecto-intercostal fascial (PIF) block and compare two volumes of injectate in canine cadavers. STUDY DESIGN: Prospective experimental cadaveric study. ANIMALS: A total of 11 canine cadavers (11.8 ± 1.9 kg). METHODS: Parasternal ultrasound-guided injections were performed within the PIF plane, between the deep pectoral and external intercostal muscles, at the intercostal space between ribs four and five. Each hemithorax was injected with 0.25 mL kg-1 (treatment low volume, LV) or 0.5 mL kg-1 (treatment high volume, HV) of 1% methylene blue dye. Treatments were randomly assigned to either right or left hemithorax, with each cadaver injected with both treatments, for a total of 22 injections. Anatomical dissections were performed to determine staining of ventral cutaneous branches of intercostal nerves, surrounding nerves and musculature and spread of injectate. The presence or absence of intrathoracic puncture was also noted. RESULTS: The PIF plane was identified and injected in each hemithorax. No significant differences between treatments LV and HV were found for number of ventral cutaneous nerve branches stained or any other analyzed variable. The ventral cutaneous branches of intercostal nerves (T3-T8) were variably stained, and the most commonly stained nerves were T5 (6 and 10), T6 (8 and 9) and T7 (2 and 7) in treatments LV and HV, respectively. Staining outside the immediate parasternal region was noted in both treatments, with greater spread away from the parasternal region in treatment HV. No intrathoracic staining was found. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided PIF injections resulted in staining of ventral cutaneous branches and parasternal musculature; however, the spread observed was inadequate to provide effective analgesia to the sternum. In vivo studies are warranted to investigate this regional anesthetic technique in veterinary patients.

Ultrasound-guided rectus sheath block: an anatomic study in dog cadavers.

OBJECTIVES: To describe the ultrasound-guided rectus sheath block technique and the anatomical spread of two volumes of methylene blue injection in dog cadavers. STUDY DESIGN: Blinded, prospective, experimental cadaveric study. ANIMALS: A total of eight dog cadavers weighing 8.9 ± 1.6 kg. METHODS: Ultrasound-guided rectus sheath injections were performed bilaterally 1 cm cranial to the umbilicus using 0.25 mL kg-1 (low volume; LV) and 0.50 mL kg-1 (high volume; HV) of 0.5% methylene blue dye. A total of 16 hemiabdomens were injected. The ultrasound image quality of the muscular and fascial plane landmarks and needle visualization were scored using a standardized scale. Cadavers were dissected to determine the distribution of the dye and to assess staining of ventral branches of the spinal nerves. RESULTS: Fewer ventral spinal nerve branches were stained in the LV group than in the HV group, at 2.00 ± 0 and 2.90 ± 0.83, respectively (p < 0.01). Ventral branches of thoracic (T) and lumbar (L) spinal nerves (T10, T11, T12, T13 and L1) were stained 25%, 100%, 75%, 25% and 0% of the time in LV group and 12.5%, 87.5%, 100.0%, 75.0% and 13.0% in HV group. A lesser extent of cranial-caudal dye distribution was observed in the LV group than in the HV group (7.1 ± 1.8 cm and 9.2 ± 1.8 cm, respectively; p = 0.03). There was no significant difference in medial-lateral spread of dye, number of test doses or ultrasound image quality scores between groups. CONCLUSIONS AND CLINICAL RELEVANCE: The results of this study suggest that, on an anatomical basis, this easily performed block has the potential to provide effective abdominal wall analgesia for the ventral midline. This study supports the potential of the rectus sheath block for abdominal procedures, and further investigations on its clinical efficacy are warranted.

Description of an ultrasound-guided erector spinae plane block and the spread of dye in dog cadavers.

OBJECTIVES: To describe a technique to perform an ultrasound-guided erector spinae plane (ESP) block and determine the distribution and potential complications after injection of two volumes of methylene blue in dog cadavers. STUDY DESIGN: Prospective experimental cadaveric study. ANIMALS: A total of eight dog cadavers weighing 9.3 ± 1.9 kg. METHODS: Ultrasound-guided injections dorsal to the transverse process and ventral to the erector spinae muscles aimed at the fifth thoracic transverse process were performed bilaterally in each dog using 0.5 and 1.0 mL kg-1 dye solution [low volume (LV) and high volume (HV) treatments, respectively]. Treatments were randomly assigned to the right or left side of each dog, resulting in a total of 16 injections. Anatomical dissections determined dye spread characteristics, including epaxial muscles spread, staining of spinal nerves, dorsal rami, ventral rami (intercostal nerves) and sympathetic trunk spread. Staining indicating potential complications (epidural, mediastinal and intrapleural spread) was recorded. RESULTS: There was complete staining of at least one dorsal ramus following all injections. A more extensive spread was observed along the muscles in the HV compared with LV (p = 0.036). No significant difference between multisegmental dorsal rami spread (six out of eight injections in each treatment) was noted. Out of 16 injections, one in LV treatment resulted in multisegmental spinal nerve staining and one in HV treatment resulted in ventral ramus (intercostal nerve) staining. Use of anatomic landmarks resulted in inaccurate identification of the fifth transverse process in at least six out of 16 injections (38%). No sympathetic trunk, epidural, mediastinal or intrapleural staining was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided ESP injections resulted in extensive staining along the epaxial muscles, as well as staining of the dorsal rami in all dogs. The incidence of dorsal rami mutisegmental spread was the same in both treatments.

Description of an ultrasound-guided thoracic paravertebral block technique and the spread of dye in dog cadavers.

OBJECTIVES: To describe an ultrasound-guided thoracic paravertebral block and determine the distribution after injection of two volumes of methylene blue in dog cadavers. STUDY DESIGN: Prospective experimental cadaveric study. ANIMALS: Twelve dog cadavers weighing 11 ± 3 kg. METHODS: Ultrasound-guided injections aimed at the fifth thoracic (T5) paravertebral space were performed in randomized order using 0.1 or 0.3 mL kg-1 dye solution (six dogs for each volume). Anatomic dissections determined dye spread characteristics, including the presence and degree of staining of spinal nerves, and the presence of intercostal and sympathetic trunk spread. Staining of mediastinum, epidural, intrapleural and contralateral thoracic paravertebral space was recorded. RESULTS: There was no significant difference in dye distribution between groups. The use of anatomic landmarks resulted in the inaccurate identification of the T5 paravertebral space. The T4, T5 and T6 paravertebral spaces were injected in four, five and three of 12 dogs, respectively. Complete staining of the spinal nerve of the thoracic paravertebral space injected was observed in 11 of 12 dogs, and partial staining in one dog in the low-volume group. Multisegmental distribution was demonstrated with staining of contiguous spinal nerves in one dog in the high-volume group, and multiple segments of intercostal (three dogs) and sympathetic trunk (four dogs) spread in both groups. No mediastinal, epidural, intrapleural or contralateral thoracic paravertebral space staining was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided injection at the thoracic paravertebral space resulted in staining of the spinal nerve in all dogs. However, T5 paravertebral space was not accurately identified using anatomic landmarks. Dye distribution was not significantly different between the two groups; therefore, the use of the lower-volume and multiple-site injections would be potentially necessary in clinical cases to achieve ipsilateral blockade of the thoracic wall.

The efficacy of intracoelomic fospropofol in red-eared sliders (Trachemys scripta elegans).

Intravenous anesthetic delivery in reptiles can be challenging. Current injectable techniques have varied induction/recovery times and anesthetic quality. This study hypothesized that intracoelomic administration of a new anesthetic, fospropofol, in turtles would result in dose-dependent anesthesia and respiratory depression. A two-part prospective trial using adult red-eared slider turtles (Trachemys scripta elegans) weighing 764 +/- 17 g was conducted to determine an effective anesthetic dose and to evaluate the anesthetic quality, duration, and respiratory effects of an efficacious dose. In part 1, six turtles were randomly administered 25-mg/ kg (low-dose [LD]) and 50-mg/kg (high-dose [HD]) fospropofol in a crossover design. Respiratory rate, immobility, and muscle relaxation scores were evaluated for 180 min. In part 2, eight turtles were administered HD fospropofol. Immobility and muscle relaxation (front and hind limb) scores and time to endotracheal intubation/extubation were evaluated until scores returned to baseline. In part 1, the LD group had significantly lower immobility and muscle relaxation scores versus the HD group over time (both P < 0.05); scores were significantly elevated from baseline for 20-120 min and 15-180 min, respectively (all P < 0.05). Although not significantly different between groups (P > 0.05), respiratory rate was significantly decreased from baseline from 10 to 120 min (all P < 0.05). In part 2, HD fospropofol decreased respiratory rate from 21.5 +/- 2.9 breaths/min to 0.1 +/- 0.1 breaths/min, similar to the results in part 1. Maximal reductions in mobility and front and hind limb motor tone occurred at 39.0 +/- 4.1, 30.8 +/- 3.6, and 24.0 +/- 3.6 min, respectively. Intubation in 7/8 turtles occurred at 45.7 +/- 5.4 min and extubation at 147.0 +/- 23.2 min. However, 2/8 turtles showed prolonged anesthetic effects, requiring resuscitative efforts for recovery. Due to the unpredictable quality and duration of anesthesia with intracoelomic fospropofol, it should be used with caution for general anesthesia in red-eared sliders at the doses and administration route investigated.

Computed tomographic laryngotracheal dimensions in adult domestic rabbits (Oryctolagus cuniculus) are positively associated with body weight and the laryngotracheal lumen is narrowest at the level of the thyroid cartilage.

OBJECTIVE: This retrospective study aimed to measure rabbit laryngotracheal dimensions at different locations on computed tomography (CT), assess the relationship of these measurements with rabbit body weight, determine the most common narrowest measurement and assess its relationship with endotracheal tube (ETT) size and body weight. ANIMALS: 66 adult domestic rabbits (Oryctolagus cuniculus) of different breeds and body weights. PROCEDURES: CT laryngotracheal luminal height, width, and cross-sectional area measurements were made at the rostral thyroid cartilage at the level of the arytenoids, caudal thyroid cartilage/rostral cricoid cartilage, caudal cricoid cartilage/cranial trachea, and trachea at the level of the fifth cervical vertebra. RESULTS: The data for every measurement of luminal airway dimensions revealed robust positive associations with body weight (P < .001). The narrowest laryngotracheal measurement was the width at the level of the caudal thyroid cartilage/rostral cricoid cartilage, and the smallest cross-sectional area was at the rostral thyroid cartilage at the level of the arytenoids. There was a strong association between body weight and the likelihood of appropriate ETT fit. To have at least an 80% chance of appropriate ETT fit with a 2.0, 2.5, and 3.0 mm ETT, the rabbits' weight predicted by the model (lower 95% confidence limit) were at least 2.99 (2.72) kg, 5.24 (4.65) kg, and 5.80 (5.21) kg, respectively. CLINICAL RELEVANCE: The laryngotracheal lumen was narrowest at the level of the caudal thyroid cartilage in rabbits, which indicates this location may be the limiting factor in determining ETT size in rabbits.

Weight-based volume of injection influences cranial to caudal spread of local anesthetic solution in ultrasound-guided transversus abdominis plane blocks in canine cadavers.

OBJECTIVE: To determine if the volume of injected local anesthetic solution affects cranial to caudal spread when performing ultrasound-guided transversus abdominis plane (TAP) blocks in dogs. STUDY DESIGN: Prospective experimental study. ANIMALS: Adult Beagle cadavers (n = 20) METHODS: Bilateral TAP blocks using ultrasound guidance was performed in 20 Beagle cadavers (mean ± SD weight, 9.3 ± 1.4 kg) using a 1:1 solution of methylene blue/bupivacaine injected at volumes of 0.25, 0.5, 0.75, and 1.0 mL/kg. Cadavers were dissected to determine injectate spread within the transversus abdominis fascial plane. RESULTS: The transversus abdominis fascial plane was adequately identified by ultrasonography, injected, and dissected in 38 beagle hemi-abdominal walls; injectate was not identified in 2 hemi-abdominal walls. Dermatomal spread (number of ventral nerve roots saturated by injected solution) was volume dependent (P = .026, Kruskal Wallis): 2.9 ± 0.74 nerve roots for 0.25 mL/kg; 3.4 ± 1.1 for 0.5 mL/kg; 4.0 ± 0.67 for 0.75 mL/kg; and 4.2 ± 1.2 for 1 mL/kg. CONCLUSION: In Beagle cadavers, the volume of injected local anesthetic solution significantly affects cranial to caudal spread within the TAP during ultrasound-guided TAP blocks. The volume of local anesthetic injected could potentially be used to augment the spread of analgesic coverage for a given surgical procedure in dogs.

Utilization of sentiment analysis to assess and compare negative finding reporting in veterinary and human literature.

Publication bias and the decreased publication of trials with negative or non-significant results is a well-recognized problem in human and veterinary medical publications. These biases may present an incomplete picture of evidence-based clinical care and negatively impact medical practices. The purpose of this study was to utilize a novel sentiment analysis tool as a quantitative measure for assessing clinical trial reporting trends in human and veterinary medical literature. Abstracts from 177,617 clinical trials in human medical journals and 8684 in veterinary medical journals published in the PubMed database from 1995 to 2020. Abstracts were analyzed using the GAN-BioBERT sentiment classifier for both general trends and percentage of neutral/negative publications. Sentiment was defined on a - 1 (highly negative) to 1 (highly positive) scale. Human-based clinical trial publications were less likely to feature positive findings (OR 0.87, P < 0.001) and more likely to include neutral findings (OR 1.18, P < 0.001) relative to veterinary clinical trials. No difference was found in reporting of negative sentiment trials (OR 1.007, P = 0.83). In both groups, the published sentiment of clinical trials increased over time. Using sentiment analysis to evaluate large publication datasets and compare publication trends within and between groups, this study is significant in its detection of significant publication differences between human and veterinary medicine clinical trials and a continued unbalanced positive sentiment in the published literature. The implications of this unbiased reporting have important clinical and research implications that require consideration.

Ultrasound-guided transversus abdominis plane block in the dog: an anatomical evaluation.

OBJECTIVE: To describe the ultrasound-guided technique to the transversus abdominis plane (TAP) block in the dog and evaluate the spread of a local anesthetic/methylene blue solution. STUDY DESIGN: Prospective experimental trial. ANIMALS: Ten adult Beagle cadavers weighing 11.1 ± 1.1 kg (mean ± SD). METHODS: Transversus abdominis plane (TAP) blocks were performed bilaterally by a single trained individual on unpreserved cadaver dogs using 10 mL of methylene blue/bupivacaine solution per site. Dissection of the abdominal wall was performed within 15-55 minutes of block to determine distribution of injectate and nerve involvement in the transversus abdominis fascial plane. RESULTS: The transversus abdominis fascial plane was adequately visualized via ultrasound and injected in twenty hemi-abdominal walls. Segmental branches of T11, T12, T13, L1, L2, and L3 were adequately stained in 20%, 60%, 100%, 100%, 90%, and 30% of injections, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: This anatomical study suggests that the transversus abdominis plane (TAP) block would provide adequate regional anesthesia of the abdomen, potentially extending to the cranial and caudal limits of the abdomen. This supports the clinical potential of this block in veterinary medicine.

Transversus abdominis plane block for exploratory laparotomy in a Canadian lynx (Lynx canadensis).

The transversus abdominis plane (TAP) block is an innovative regional anesthetic technique using local anesthetic that is gaining popularity in the analgesic management of human patients undergoing abdominal surgery. Needle placement in the TAP block is within the facial plane between the internal oblique and transversus abdominis muscles and involves the abdominal and thoracic nerves. Successful blockade generally involves spinal nerves T10-L1 and may induce sensory blockade as far cranially as T7, thus producing analgesia for abdominal surgery. Human studies suggest that this regional anesthetic technique may provide postoperative analgesia of the abdominal wall for up to 48 hr. Because of the extent and duration of sensory blockade, this novel technique with bupivacaine was used on a Canadian lynx (Lynx canadensis), possibly providing 8-10 hr ofintra- and postoperative analgesia concurrent to exploratory laparotomy for removal of a gastric foreign body.

Protein electrophoresis in cranes with presumed insect bite.

BACKGROUND: Serum protein electrophoresis (SPE) has emerged as a potentially valuable diagnostic tool in avian medicine; yet, there is limited information regarding SPE in cranes. Since 2000, 20 cases of unilateral periocular or facial soft tissue swelling, blepharitis, feather loss, and ocular or nasal discharge attributed to insect bite hypersensitivity were observed in cranes from a captive breeding center. SPE may be useful for evaluating these lesions. OBJECTIVE: The aim of this study was to characterize the inflammatory response in cranes with hypersensitivity reactions using SPE. METHODS: Serum samples from 7 cranes diagnosed with hypersensitivity reactions were submitted to a diagnostic laboratory for agarose gel electrophoresis. Results were compared to those in control serum samples obtained from the same cranes during routine physical examination, when they were clinically healthy. RESULTS: Total protein and a- and g-globulin concentrations were significantly increased and albumin/globulin ratios were significantly decreased in serum samples from cranes with hypersensitivity lesions compared with control samples. CONCLUSIONS: Using SPE, we documented changes in protein fraction concentrations in cranes with clinical signs of hypersensitivity. The increase in alpha- and gamma-globulin concentrations suggested inflammation and antigenic stimulation, consistent with a Type I hypersensitivity reaction.

Respiratory rates and arterial blood-gas tensions in healthy rabbits given buprenorphine, butorphanol, midazolam, or their combinations.

The objective of this study was to evaluate the respiratory effects of buprenorphine, butorphanol, midazolam, and their combinations in healthy conscious rabbits. Six adult female New Zealand white rabbits were anesthetized briefly with isoflurane by mask to allow placement of a catheter into the central ear artery. After a 60-min recovery period, a baseline arterial sample was obtained. Animals then were injected intramuscularly with either 0.9% NaCl (1 mL), buprenorphine (0.03 mg/kg), butorphanol (0.3 mg/kg), midazolam (2 mg/kg), buprenorphine + midazolam (0.03 mg/kg, 2 mg/kg), or butorphanol + midazolam (0.3 mg/kg, 2 mg/kg). Arterial blood gases were evaluated at 30, 60, 90, 120, 180, 240, and 360 min after drug administration. All drug treatments caused significant decreases in respiratory rate, compared with saline. Buprenorphine and the combinations of midazolam-butorphanol and midazolam-buprenorphine resulted in statistically significant decreases in pO(2). No significant changes in pCO(2) pressure were recorded for any treatment. Increases in blood pH were associated with administration of butorphanol, midazolam, and the combinations of midazolam-butorphanol and midazolam-buprenorphine. In light of these results, buprenorphine and the combinations of midazolam-buprenorphine and midazolam-butorphanol result in statistically significant hypoxemia in rabbits that breathe room air. The degree of hypoxemia is of questionable clinical importance in these healthy subjects. Hypoxemia resulting from these drug combinations may be amplified in rabbits with underlying pulmonary or systemic disease.

Histamine release associated with intravenous delivery of a fluorocarbon-based sevoflurane emulsion in canines.

The purpose of this study was to evaluate the effectiveness of a novel fluorocarbon-based sevoflurane emulsion in dogs previously shown to produce short-term rodent anesthesia. On the basis of an unexpected allergic-type clinical reaction, we also tested the hypothesis that this type of formulation causes histamine release and complement activation. Physiological parameters, plasma histamine levels (radioimmunoassay), and complement activation (enzyme immunoassay) were quantified in response to emulsion components, including F13M5 (the emulsion's fluorocarbon-based polymer) and methoxy poly(ethylene glycol) 5000 (the polymer's hydrophilic block). Although the emulsion produced general anesthesia in dogs, they also experienced hypotension and clinical signs suggestive of an allergic-like response (i.e., vasodilation, urticaria, and pruritus upon recovery). Emulsions lacking sevoflurane failed to induce anesthesia but did elicit the allergic response. Plasma histamine levels were significantly increased following injection of micellar solutions of F13M5. Direct complement activation by the emulsion or its components was weak or absent. An allergic response leading to histamine release, likely initiated by the F13M5 component via an immunoglobulin pathway, is associated with an intravenous fluorocarbon-based emulsion of sevoflurane. Subsequently, its usefulness in medicine in its present formulation is limited.